General Information On Installation - Grundfos DMH 28X Installationsanleitung

5.3 Weight
Pump Dosing head
model material
Stainless steel
DMH 280 1.4571
Alloy C-4, 2.4610
Stainless steel
DMH 281 1.4571
Alloy C-4, 2.4610
Stainless steel
DMH 283 1.4571
Alloy C-4, 2.4610
Stainless steel
DMH 285 1.4571
Alloy C-4, 2.4610
Stainless steel
DMH 286 1.4571
Alloy C-4, 2.4610
Stainless steel
DMH 287 1.4571
Alloy C-4, 2.4610
Stainless steel
DMH 288 1.4571
Alloy C-4, 2.4610
5.4 Stroke volume
Pump model
DMH 280
DMH 281
DMH 283
DMH 285
DMH 286
DMH 287
DMH 288
5.5 Materials
Pump housing material
• Pump housing: Al 226.
AR control unit enclosure
• Upper part of enclosure: PPO blend
• Lower part of enclosure: aluminium.
Warning
Observe the chemical manufacturer's safety
instructions when handling chemicals!
Make sure that the pump is suitable for the actual
dosing medium!
The resistance of the parts that come into contact
with the media depends on the media, media
temperature and operating pressure. Ensure that
Caution
parts in contact with the media are chemically
resistant to the dosing medium under operating
conditions!
Further information on resistance with regard to the
Note media, media temperature and operating pressure is
available on request.
Weight [kg]
Single-head Double-head
pump pump
13.7 20.4
13 19
36 54
43 64
45 71
45 71
36 54
3
Stroke volume [cm ]
0.35
1.1
6
12
25.3
5.4
2.33
5.6 Data of contact pressure gauge for diaphragm
leakage detection (optional)
Following data is not valid for contact pressure
Note
gauges in explosion-proof version.
The contact pressure gauge has a reed switch with electrically
isolated contact output, maximum switching power 10 W for DC
current or 10 VA for AC current. The maximum switching voltage
is 75 V for DC current or 50 V for AC current, maximum switching
current 0.5 A.
The switching function is set up as an NC contact, i.e. if the
diaphragm breaks, the current circuit is interrupted.
The pressure gauge has a 2-metre cable.
6. Installation

6.1 General information on installation

Warning
Observe the specifications for the installation
location and range of applications described in
section 3. Technical
Warning
Faults, incorrect operation or faults on the pump or
system can, for example, lead to excessive or
insufficient dosing, or the permissible pressure may
be exceeded. Consequential faults or damage must
be evaluated by the operator and appropriate
precautions must be taken to avoid them!
Warning
Risk of hot surfaces!
Pumps with AC motors may become hot.
Allow a minimum space of 100 mm to the fan cover!
A positive pressure difference of at least 2 bar is
required between the suction valve and the
discharge valve in order for the dosing pump to
operate correctly.
Note
If the total counter-pressure (at the dosing point) and
geodetic height difference between the suction valve
and the dosing point is less than 2 bar (20 m WC), a
pressure-loading valve must be installed immediately
before the dosing point.
data.
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